Stimulation of tanning by DNA fragments or single-stranded DNA

Abstract

A method of increasing pigmentation in mammalian skin, as well as protecting mammalian skin against ultraviolet damage, is disclosed. Also disclosed is a method of increasing pigmentation in mammalian cells, as well as a method of enhancing melanin production in mammalian melanocytes. A preparation useful in the present methods is additionally disclosed. The methods comprise administering to the epidermis or to the cells DNA fragments, either single- or double-stranded, or a mixture of both, or deoxynucleotides, in a liposomal preparation or other appropriate vehicle. The preparation includes DNA fragments or deoxynucleotides and an appropriate delivery vehicle, such as liposomes.

We claim: 
     
       1. A topical preparation for increasing pigmentation in mammalian skin, comprising DNA fragments, either single- or double-stranded, or a mixture of both, or deoxynucleotides, in an amount sufficient to increase pigmentation in mammalian skin, in a delivery vehicle. 
     
     
       2. The preparation of claim 1, wherein the delivery vehicle is liposomes. 
     
     
       3. The preparation of claim 1, further comprising diacylglycerol. 
     
     
       4. The preparation of claim 1, wherein the concentration of the DNA fragments is 0.05 to 10 mg/ml. 
     
     
       5. The preparation of claim 1, wherein the DNA fragments are dinucleotides. 
     
     
       6. The preparation of claim 5, wherein the concentration of the dinucleotides is 25 to 100 μM. 
     
     
       7. The preparation of claim 1, wherein the DNA fragments are ultraviolet-irradiated prior to commercial distribution of the preparation. 
     
     
       8. A topical preparation for increasing pigmentation in mammalian skin, comprising a dinucleotide selected from the group consisting of: thymidylic acid dinucleotide (d(pT) 2 ), and deoxyadenylic acid dinucleotide (d(pA) 2 ), in an amount sufficient to increase pigmentation in mammalian skin, in a delivery vehicle. 
     
     
       9. The preparation of claim 8, wherein the delivery vehicle is liposomes. 
     
     
       10. The preparation of claim 8, further comprising diacylglycerol. 
     
     
       11. The preparation of claim 8, wherein the concentration of the dinucleotides is 25 to 100 μM. 
     
     
       12. The preparation of claim 8, wherein the dinucleotides are ultraviolet-irradiated prior to commercial distribution of the preparation.